Estimating Uncertainty in Party Policy Positions Using the Confrontational Approach

Tom Louwerse, Huib Pellikaan

Abstract

This research note extends the confrontational approach to estimating party policy positions by providing a way to estimate uncertainty associated with the measurements. The confrontational approach is a flexible method of determining party policy positions, which is ideally suited to measure parties’ positions on issues that are specific to a country or period in time. We introduce a method of estimating the uncertainty of confrontational estimates by restating the approach as a special case of an item response theory, opening up the possibility of using the confrontational approach not only as a descriptive tool but also as a means of testing hypotheses on party policy preferences. We illustrate our model using analysis of the 2010 Dutch parliamentary election and the 2009 European elections.